PREPARATION AND CHARACTERIZATION OF THE SUPERCONDUCTING SYSTEM BI1-XPBXSRCACU2OY

The superconducting properties of the system Bi1-xPbxSrCaCu2Oy have been studied as a function of lead concentration and preparation conditions. Energy dispersive x-ray analysis indicates the nominal stoichiometry is preserved up to x = 0.2 and for this concentration, zero resistance occurs at 97 K. Magnetically modulated microwave absorption measurements provide a global probe of the samples and show that resistance measurements alone can give a false impression of the quality of the materials.